Centrifugal countercurrent exchange device



14, 1956 w. J. PODBIELNIAK ETAL 2,758,784

CENTRIFUGAL COUNTERCURBENT EXCHANGE DEVICE Filed Aug. 2. 1951 4 Sheets-Sheet l Aug. 14, 1956 w. J.,PODB|ELN|AK ET AL 2,758,784

CENTRIF'UGAL COUNTERCURRENT EXCHANGE DEVICE Filed Aug. 2, 1951 4 Sheets-Sheet 2 14, .1956 W. J. PODBIELNIAK ET AL 2,758,784

CENTRIFUGAL COUNTERCURRENT EXCHANGE DEVICE 4 Sheets-Sheet 3 Filed Aug. 2, 195] Aug. 14, 1956 w. J. PODBIELNIAK ETAL 2,758,784

CENTRIFUGAL COUNTERCURRENT EXCHANGE DEVICE Filed Aug. 2, 1951 4 Sheets-Sheet 4 United States Patent CENTRIFUGAL 'COUNTERCURRENT EXCHANGE DEVICE Walter J. Podbielniak, Wladzia G. Podbielniak, and Collin M. Doyle, Chicago, 'IlL; said Doyle assignor to Walter J. Podbielniak and Wladzia G. Podbielnialr Application August 2, 1951,Serial No. 239,992

6 Claims. (31. 2ss 1s The present invention relates to improvements in centrifugal countercurrent exchange devices, for example, of ,the general character described in the prior patents and pending applications of one of us (Walter J. Podbielniak), such as Patent No. 2,286,157, granted'June 2, 1942 and applications Serial Nos. 111,218 and 230,313, filed respectively August 19, 1949 and June 7, 195 1. The former application has since matured into Patent No. 2,670,132 granted February 23, 1954.

-In such exchange devices, liquids which are immiscible or partly immiscible and of different densities are caused to travel in concurrent with respect to each other while passing through a rotor, revolving at a high rate of speed,

.so as to exert substantial centrifugal force uponthe liquids passing through the device. In general, the purpose-of such countercurrent exchange is to secure solvent action of one of the liquids upon a constituent or constituents held in solution in theother. Since in such devices, highly effective countercurrent exchange and solvent action can be secured with an extremely short time of travel through the machine, the use of such machines has become very widespread in processes Where extremely rapid andetfeclive action is required by reason of the instability of the more valuable materials involved; for example, in .the extraction of antibiotics such as penicillin, streptomycin, aureomycin, chloromycetin and the like.

It has beenv the practice, in conducting such operations with devices of the type hereinbefore referred to, to first clarify and remove solids. from the liquids employed in the eountercurrent exchange or solvent extraction process. Thus, in the preparationof penicillin, it has hitherto been the practice to clarify the broth in which the Penicillium organism is cultivated before subjecting the-clarified broth to. countercurrent exchange with the amyl acetate or other solvent that may be employed for the extraction of the penicillin from the broth. This clarification has been effected,,for example, by the use of centrifugal separators, vacuum filters of various types, plate filter presses and the like. Such clarifying and filtering operations require additional time, which may be destructive of the active principle involved, as well as expensive apparatus and additional labor for cleaning and like tasks.

Other processes in which countercurrent solvent action is desirable present similar difficulties because of the presence of solids and thus have hitherto required .preliminary clarification or filtration before the solvent-treatment. For example, in the extraction of vitamins from fish liver oil, ground liver tissues may be present in the oil subjected to extraction. In the extraction ,of vegetable oils, in some operations, the solid material from which the oil. is to be extracted may be ground or shredded and carried in a slurry, in which form it would be desirable to subject'it to the extraction process. is that of chemicalreaction mixtures resulting from reduction-processes inwhich finely divided metals, such as iron are employed, and where the reaction mixture is IeftLin liquidform and'itis. desirable toremove a par- ;ticular-constituentrfrom it'by solvent extraction. By the Another example i 2,758,784 Patented Aug. .14,- .1955

ice

present invention, as hereinafter described, we are enabled to subject the solids-containing liquids or .slurries them which aconstituent is 'to be extracted by solvent action, directly to the centrifugal countercurrent action of :a suitable solvent, .with'the effectiveness and speed .of action that have hitherto been-secured in the treatment of clarified solutions in such devices. Theinvention-willbe fully understood from the following description .thereof,.illustrated by the accompanying drawings wherein: n

Fig. 1 is a side elevation of a device embodying the present invention;

Fig. 2 is a front elevation of the deviceofFig. l, .partly in section;

Fig. 3 is a sectional view taken through the axis ofthe rotor of the device of Figs. 1 and 2;

Fig. 4 is a side view of the .outer face of ,an inner .disk forming part of .the rotorof Fig. 3;

Fig. 5 is a detail sectional View through the ,axis of a modified form of rotor showing the arrangement of a perforated spiral asemployed in the rotor of Fig. 5;

Fig. 6 is a diagrammatic view showing a form of arrangement of spiral partition walls with spacing lugs for spacing .the walls.

Fig. 7 .is a broken detail view in perspective of atom of the spiral of Fig. 6; and

Fig. 8 is a diagrammatic View showing a form of arrangementlo'f the concentric rings as usedin the rotorof Fig. 5.

Referring more particularly to Figs. 1 to 4, inclusive, of the drawings, the numeral 10 indicates a supporting framework upon which are mounted suitable journal bearings 1,1, in which are rotatably carried theshaft 12 upon which is mounted the rotor 15. Surrounding the rotor is a stationary casing likewise carried by the supporting frame 10 and consisting of a lower fixed portion 16 and an upper portion 17, pivoted as at 18 to permit of its being raised for access to the rotor.

In the device as illustrated in the drawings, the countercurrent or solvent exchange takes place within the rotor 15, which is rotated at a high rate of speed, for example from 2,000 to 5,000 R. P. M. or even higher, thus developing substantial centrifugal forces within the rotor. The heavier liquid is introduced at an inner .point in the rotor and travels outwardly under the action of the centrifugal force, leaving at or near the outermost portion of the interior of the rotor. Similarly the lighter liquid is introduced at an outer point in the rotor, and is forced inwardly through the rotor against the outwardly traveling heavier liquid to eifect the desired countercurrerit or solvent action. The light liquid, after this process has been conducted, is withdrawn'from" an inner point within the rotor. In the ensuing description of the apparatus, "it will be assumed that the heavier liquid is the liquid initially containing the valuable material to be extracted, and also carrying accompanying solids, for example, the mycelia of a penicillin broth; and it will be assumed that the lighter liquid is the solvent which is being employed to extract the valuable material from the heavier liquid.

From the preceding description, it will be apparent that it is necessary to supply the heavier liquid to the operation and to withdraw the lighter liquid from the operation at points near the interior of the rotor; and that it will be necessary to supply the lighter liquid within the rotor and remove the heavier liquid therefrom (together with suspended solids) at the outer portion of the rotor. For this purpose, the shaft 12 is provided with two sets of internal concentric conduits, as diagrammatically illustrated in Fig. 3 of the drawings. As shown in Fig. 3 of'the drawings, the shaft 12 is provided internally at=the left with concentric conduits, the inner one being designated 19 and the annular conduit surrounding it being designated 20. The inner conduit 19 passes through the shaft and communicates with a pipe 21, as shown in Fig. 2, by which the heavy liquid, containing solids, is to be supplied to the rotor. The annular conduit 20, which surrounds the conduit 19, likewise extends through the shaft and communicates with the pipe 22, by which the light liquid is removed from the apparatus after the operation within the rotor has been completed.

Similar conduits are provided in the opposite portion of the shaft for supply of the light liquid to the rotor and removal of the heavy liquid with suspended solids. Thus, as shown in Fig. 3 at the right, the shaft 12 is provided with an internal conduit surrounded by an annular conduit 26. The internal conduit 25 extends through the shaft and communicates with the pipe or conduit 27, as shown at the right in Fig. 2, and through this pipe 27, the light liquid is forced into the rotor. The inner conduit 25 and the pipe 27 communicate through a chamber 28 formed in the stationary cap 29, in which the end of the shaft 12 rotates. The annular conduit or passageway 26 communicates with the pipe 30 by which the heavy liquid (and suspended solids) are withdrawn from the system after the countercurrent exchange operation has been carried out. The annular conduit 26 communicates with the pipe 30 through a chamber 31, likewise formed in the stationary cap 29, suitable sealing means 32 being provided to prevent intermixture of the liquids. It will be understood that similar arrangements are provided at the opposite end of the shaft for communication between the conduits 19 v and 20 and the pipes 21 and 22, respectively.

The rotor, as shown more particularly in Fig. 3, is formed as a cylindrical casing made up of two side members or disks 35 and 36 and a peripheral cylindrical member 37, rigidly secured to each other and to the shaft to form a closed chamber.

Within the side members or disks 35 and 36 of the rotor and spaced therefrom to provide a small clearance of say to 43 inch are the inner disks 38 and 39, respectively. As will be pointed out hereinafter, the inner-disk passageways thus formed and which are respectively referred to by numbers 40 and 41, serve for the discharge of heavy liquid containing suspended solids from the rotor.

Annular passageways of progressively increasing radius are formed in the rotor, suitably by a spiral band, as shown in Patent 2,286,157, hereinbefore referred to, or preferably by cylindrical rings. Thus, as shown in Fig. 3, the inner surfaces of the inter-disks 38 and 39 are provided with circular grooves 42, within which are firmly held the edges of the concentric perforated rings or partition Walls 43. As shown in Fig. 3, the spacings between the concentric perforated rings 43 are equal although, if desired, these spacings may either increase or decrease with increasing radius. If desired, the grooves may be formed as spirals, and a continuous spiral band employed instead of concentric rings, in which case the turns of the spiral for the partition walls may be regarded, in effect, as if they were rings in the structure as hereinafter described. The concentric rings 43 are perforated, as more fully hereinafter described, so as to secure the desired flow of the liquids in the rotor with the required countercurrent exchange or solvent action and with proper handling of the solids contained in the liquids.

It will be apparent that in the conduct of the operation within the rotor, the necessity for handling solids without building up excessive deposits within the rotor presents stringent requirements, particularly when the solids are of the character found in actinomycete and mold broths, fermenation beers, and the like and when effective countercurrent exchange or solvent action is to be secured. Thus it has been found that, to effectively handle solids and secure adequate countercurrent exchange action, the perforations in the concentric rings 43 should be from 0.15 to 0.3 inch in diameter and preferably approximately 0.250 inch in diameter. The perforations should be spaced apart from /2 inch to 1% inch, and preferably from /2 inch to 1 inch, between centers, and the perforations in each ring should be staggered with reference to those on opposite sides of it, so that every perforation in each ring will be directly opposite solid unbroken portions of the rings on both sides. This is illustrated by the arrangement of the perforations 44 in rings 43, as shown in Fig. 3. In this way, the jet action of the liquids passing through the perforations 44 is directed against an imperforate portion of the next ring 43 and tends to wash solids away from such irnperforate portion, if any have accumulated thereon. Adequate intermixing takes place in the passage of liquids through the perforations and separation takes place in the spaces between rings or turns.

The spacing between the concentric rings 43, when the latter are equidistant from each other, may vary, for example, from A; inch to /2 inch, although a clearance in the general order of about inch has been found most satisfactory. When the clearance between rings is variable, for example, as disclosed in the prior application of Walter J. Podbielniak, Serial No. 111,218, filed August 19, 1949, now Patent No. 2,670,132 granted February 23, 1954, it may vary from approximately A2 inch to approximately 12 inch or even more in the same rotor.

The perforations in each ring or turn are substantial 1y uniform in size, to prevent lack of uniformity in distribution of the light and heavy liquids and to secure substantially uniform mixing and interchange between the liquids. Preferably the perforations are throughout of substantially uniform size, although somewhat larger perforations may be used in the outer turns or rings, if desired.

In supplying the heavy liquid within the rotor, provision is made so that the light liquid being removed and which, in the illustrative case here presented, is the solvent liquid carrying the valuable constituent removed from the heavy liquid, is adequately clarified before removal. Thus, as shown in Fig. 3, the conduit 19 by which the heavy liquid carrying solids and the valuable material is supplied to the rotor, communicates through the opening 45 drilled from the axis of the shaft to the interior opening 46 in a plug 47 which extends radially into the rotor a sufficient distance to provide an adequate clarifying area for the light liquid being removed. Thus the plug 47 may pass through openings suitably provided for the purpose in several of the inner rings 43, for example, 3. The heavy liquid is thereby discharged at this point into the clearance space between two of the rings 43. The area within the rotor between the point at which the heavy liquid is supplied within the rotor and the outer surface of the shaft 12 is thus provided for adequate clarification of the light liquid before it leaves through the opening 48 in the shaft to enter the annular conduit 20. The light liquid thus removed passes out through the conduit 20 and is withdrawn through the external pipe 21, previously referred to.

It will be understood that while only one plug or nozzle 47 for the supply of heavy liquid within the rotor is shown, with its connecting opening 45 leading to the conduit 19, that a plurality of such nozzles or plugs may be supplied for the purpose at angular intervals around the shaft. Similarly, a number of openings 48 may be provided at angular intervals around the shaft 12 for removal of light liquid after the operation has been completed, although only one is shown in Fig. 3.

The light liquid which is introduced into the apparatus is supplied, under sufficient pressure to force it through the rotor, at a point near the outer circumference of the rotor chamber. A space is provided within the chamber beyond the point of introduction of the light liquid to permit adequate separation of light liquid from the swea e l heavy liquid being discharged from the apparatus and to provide suitable means to secure the effective discharge vof solids in suspension in the heavy liquid. Thus, as illustrated in Fig. 3, light liquid entering through the conduit 25, passes through an opening 50 drilled radially through the shaft and communicating with the conduit 51 drilled radially through the inner disk 38. The conduit 51 is closed at its outer end by a screw plug 52. A perforated distributing pipe 53, extending transversely between the inner disks 38 and 39, communicates through a drilled opening 54 with the conduit 50. The perforations in the conduit or pipe 53 are directed inwardly. Thus light liquid entering through the conduit 25 passes through the openings or conduits '50 and 51 and discharges into the pipe 53 and from it into the working area of the rotor.

As will be readily understood, a number of the transverse perforated pipes or conduits 53 may be provided at angular intervals around the interior of the rotor, each communicating with the conduit 25 in the shaft 12 in the same manner as already described in connection with the pipe 53.

The conduits for the supply of light liquid being spaced internally from the outer walls of the rotor chamber, a space is provided thereby for the effective separation of light liquid which may be carried by the heavy liquid in dispersion or in emulsified form. Means are provided within this space beyond the light liquid distributing pipes 53 to avoid accumulation and secure removal of solids. For example, a slope or angle is given to the effective internal surface of the rotor toward the outermost point within the rotor at which the discharge of heavy liquid and suspended solids is effected. In the form of construction shown in Fig. 3, to provide this effective sloping outer wall for the working chamber of the rotor, the meeting frustroconical baflles 56 and 57 are provided. These are symmetrical with respect to each other and are fastened or welded together where they meet at 58, to form, in effect, a single piece which is held in position by the shoulders 59 formed on the inner surface of the cylindrical outer wall 37 of the rotor. lFrustroconical baffles 56 and '57 thus provide angular or sloping surfaces leading to the passageways '60 and 61, respectively, between the outer edges of the inner disks 38 and 39 and the outer wall of the rotor. The outer edges of the inner disk-s 38 and 39, respectively, are rounded and any angles within the rotor forming parts of this passageway are built up to rounded form, for example, with weld metal as illustrated at 62, so that no pockets or enlargements are present for the lodging or accumulation of solids. In its preferred form, a smooth, gradually narrowing passageway for the heavy liquids and suspended solids is thus provided, leading into the interdisk spaces 40 and 41. This passageway is dimensioned so that, with the normal rate of flow of heavy liquid, its velocity will be such as to carry solids with it; for example, to 50 feet per second.

By employing the inter-disk space as hereinafter described for the inward flow of the heavy liquid carrying suspended solids, we are able to maintain the solids in suspension and prevent their settling out during their passage from the system. It has been found that the centrifugal force in the rotation of the rotor in its operation tends to produce a swirl or agitation in the liquid passing through this inter-disk space. In order to prevent this agitation becoming excessive (and in some cases it has been found to build up in an uninterrupted interdisk space to such an extent as to cause frictional pressure drops in the order of 100 pounds per square inch), interrupted or staggered vanes 65 are provided between the walls of the two inter-disk spaces, generally being secured to the inner disk, as illustrated in Fig. 4. In general, it is preferred that these vanes be radial or ap-, proximately radial and that they be broken or staggered so that no continuous lateral or circumferential passageway for liquid is provided. Precise positioning of these 6 vanes is not required; it is only necessary that they be present in such positions as to break up the circumferential swirl of liquid set'up'by the rotation of the rotor and thereby to prevent the building up of the excessive pressure drops which are secured when no vanes are present.

A further advantage resulting from the use of short staggered vanes is that no complete barriers against circumferential movement of the heavy liquid carrying suspended solids is presented. In a satisfactory arrangement, it has been found that the pressure drop may be in the order of 25 to 30 pounds per square'inch. The heavy liquid travels inwardly through the inter-disk spaces. At one side (as shown at the right'in Fig. 3) the inter-disk space 40 communicates through opening 66 drilled in the shaft 12 with the annular conduit 26, through which the heavy liquid is discharged from the system as hereinbefore described. The inter-disk space 41 on the opposite side communicates with a longitudinal passageway 67 milled in the shaft and this in turn also communicates through the opening 68 drilled through the shaft with the annular conduit 26.

Inorder that the proper inter-disk separation may be maintained between the inner-disks 38 and 39 and the outer rotor disks 35 and 36, respectively, spacing studs 70 are screwed into the outer walls of the inner disks 323 and 39 at suitable angular intervals.

It will be apparent from the preceding description that the solids suspended in the liquid being discharged from the rotor, notwithstandingthe large centrifugal forces developed, will be carried out of the rotor with the liquid. The angular or sloping outer rotor walls formed by the baffies 56 and 57 and the provision of a continuous passageway out of the body of the rotor into the inter-disk space without enlargements or pockets prevents lodgement or deposition of the solid material; and in the inter-disk space, the controlled agitation resulting from the swirl of the liquid and the use of the staggered vanes likewise maintains the solid matter in suspension. It will be readily understood that with a smaller rotor or a rotor of narrower width, a single section of the frustroconical baffle might be employed, as will appear from the following description of the modification of the rotor'sh'own in Fig. 5. Suitable means are provided for driving the rotor at a suitable speed, say 2,000 to 5,000 R. P. M., such as the sheave 72, driven through belt 73 from an electric motor or other suitable power source, not shown.

In Fig. 5 a modified form of rotor is shown. In this form of construction, additional provision is made for the clarification of the light liquid removed from the system.

As shown in Fig. 5, the drive shaft carrying the rotor is represented by the numeral 75. On the shaft 75 is mounted the rotor 76, suitably formed as a disk 77 with a cylindrical flange 78, forming a cup-like chamber or cylindrical space which is closed by a disk 79, suitably held in position by a ring nut 80. Within the rotor, and spaced from the disk 77, the inner disk 81 is provided. Opposite it, a disk 82 is held in position by the disk 79. The opposite faces of the disks 81 and 82 are provided with matching grooves 83 and 84, respectively, into which are forced the perforated cylindrical rings 85. These cylindrical rings are perforated as are the rings 43 in the construction shown in Fig. 3, the pen forations being of similar size and being staggered similarly, to those as described in connection with the cylindrical rings 43. In the form of construction illustrated in Fig. 5, however, the spacings between the respective concentric rings decrease as the radius increases, suitably as an inverse function of the radius. The spacings between these rings may be varied, for example, as described in the prior application of one of us, Serial No. 111,218, previously referred to. The concentric rings, as hereinbefore described in connection with the form of construction shown in Fig. 5, occupy only a part of the space between the disks 81 and 82. Within the inner most of the concentric rings 85, the opposing inner walls of the disks 81 and 82 are recessed as at 87, and in this recessed portion a spiral perforated band 8% is wound. In order to space the turns of this spiral, as illustrated in Figs. 6 and 7, in forming the perforations, the metal is not completely removed, but is turned downwardly and forms spacing lugs or ears 90. In the form of construction shown in Fig. 5, the heavy liquid entering the rotor comes in through the conduit 92 formed in the shaft 75, passes through the opening 93 drilled approximately radially through the shaft and into the plug or nozzle 94 which extends radially to the space between the outer turn of the spiral band 89 and the innermost of the concentric rings 85. The entire area taken up by the turns of the spiral band is thereby made available and used for the clarification and demulsitication of separated light liquid, which passes out from the innermost portion of the rotor through the radial opening 96 drilled in the shaft 75, to enter the annular conduit 97, through which it passes out of the system. Light liquid is supplied through the internal conduit 100 on the opposite side of the shaft 75, passes through the radial hole 101 drilled in the shaft and through the radial conduit 102 drilled in the inner disk 81, discharging into the rotor through the perforated distributing pipe 103, corresponding to the distributing pipe 53 of Fig. 3. As in the construction of Fig. 3, a frustroconical baffle or guide 105 is secured within the rotor beyond the perforated conduit 103, this frustroconical guide forming a sloping or angular outer wall for the working chamber of the rotor. It is held in position by suitable shoulders 106 and 107 formed on the inner walls of the rotor. Any solids present are thereby guided in the direction of the discharge opening for the heavy liquids. As in the form of construction shown in Fig. 3, the inner wall of the rotor and the corresponding or opposing surface of the inner disk 31 are shaped to provide a smooth continuous discharge passageway without enlargement or cavities for the lodging and deposition of solid material. In the form shown in Fig. 5, an inter-disk space 107a is provided for the discharge of the heavy liquid, the swirl within this space and the deposition of solids being prevented or controlled by the staggered vanes 108, placed as described in connection with the rotor shown in Fig. 3. The inter-disk space communicates through the axial opening 110 drilled in shaft 75 with the annular conduit 111, by which the heavy liquid and suspended solids are discharged from the system. A plurality of such openings may be provided at angular intervals around the shaft.

The apparatus of the present invention has been successfully used in many different applications for the extraction of active principals. Thus it has been employed in the solvent extraction of whole chloromycetin broth with various solvents, such as ethyl acetate, arnyl acetate and other solvents; for the extraction of aureornycin from the whole broth, using butyl alcohol as a solvent; and for the extraction of penicillin from whole penicillin broth with butyl or amyl acetate. In each of the above cases, although the microorganism and its growth products were present, highly effective recoveries in the order of 90 to 95% and higher of the desired active constituent were secured with continuous discharge of solids with the accompanying liquid constituents of the extracted broth at operating speeds of 3,000 to 5.000 R. P. M. It has likewise been employed in the extraction of vitamin A from a slurry consisting of cornminuted fish livers and fish liver oil in alkaline solution, the solvent being a hexane fraction. It has aso been employed in the extraction of organic reaction mixtures containing finely divided iron and various iron salts in suspension, with organic solvents, the solid matter being successfully carried off in the operation and hi h efiiciency of extraction being secured.

As is readily apparent, the solids present may be initially carried by the entering light liquid steam, in which case "I? the distributing pipes through which the light liquid is introduced into the rotor should be provided with openings of a size sufficient to prevent clogging, say 0.125 to 0.250 inch.

Although the present invention has been described in connection with the details of specific embodiments thereof, it is not intended that the details shall be regarded as limitations upon the invention, except insofar as included in the accompanying claims.

We claim:

1. in apparatus for countcrcurrent exchange between at least partly immiscible liquids of different densities, one of which carries solids, a rotor provided internally with a rotor chamber, spaced partition walls within said chamber surrounding the axis of the rotor and forming successive passages of increasing radius, the elements of said walls being parallel to the axis of said rotor, openings in each of said walls for passage of fluids therethrough, the openin s in each of said walls being of substantially uniform size and spaced over the surfaces of said partition Walls intermediate their edges, the openings in adjacent walls being staggered with respect to each other to provide an imperforate portion of an adjacent wall opposite each opening in each well through the rotor except for the innermost and outermost perforated. partition walls, closure means being provided at the ends of said walls to prevent flow therebetween except through said openings, the outer portion of said rotor chamber being free of said partition walls and provided internally with a sloping surface, the outermost portion of said sloping surface extending to a discharge passage for the heavier liquid and solids carried thereby, means for supplying heavier liquid to and removing lighter liquid from the inner portion of said rotor chamber, means for removing heavier liquids carrying suspended solids from the outermost portion of said rotor chamber through said discharge passage and means for introducing lighter liquid into the outer portion of said rotor chamber, said last named means being spaced internally from the opening of the aforesaid discharge passage for heavier liquid and solids to provide an outer space within the rotor chamber for demulsifying the heavy liquid prior to its removal.

2. The apparatus of claim 1 wherein the partition walls are in the form of cylindrical bands.

3. In apparatus for countercurrent exchange between at least partly immiscible liquids of different densities, one of which carries solids, a rotor provided internally with a rotor chamber, spaced partition walls within said chamber surrounding the axis of the rotor and forming successive passages of progressively increasing radius, the elements of said walls being parallel to the axis of rotation of said rotor,'openings in said walls for passage of fluids there through, the openings in. each of said Walls being of substantially uniform size and spaced over the surfaces of sald partition walls intermediate their edges, said openings in adjacent walls being staggered with respect to each other, the outer portion of said rotor chamber being free of said walls and provided internally with a sloping surface, the outermost portion of said sloping surface extending to a discharge passage for the heavier liquid and solids carried thereby, a nozzle extending into the rotor chamber from the innermost portion thereof for supplying heavier liquid to said chamber, said nozzle passing through a plurality of the innermost partition walls whereby the inner portion of said rotor chamber serves to effect demulsificatron and clarification of the lighter liquid prior to its removal therefrom, means for removing the lighter liquid from the innermost portion of said rotor chamber, means for removing heavier liquids carrying suspended solids from the outermost portion of said rotor chamber through said discharge passage, and means for introducing lighter liquid into the outer portion of said rotor chamber, said last mentioned means being spaced internally from the opening of the discharge passage for heavier liquids and solids, to provide an outer space within the rotor chamber for demusifying the heavy liquid prior to its removal therefrom.

4. The apparatus of claim 3 wherein the partition walls are in the form of cylindrical bands.

5. In apparatus for countercurrent exchange between at least partly immiscible liquids of different densities, a rotor provided internally with a rotor chamber, spaced partition Walls within said chamber having openings for passage of fluids therebetween, means for removing heavier liquid from and supplying lighter liquid to the outer portion of said rotor, a nozzle extending into the rotor chamber from the innermost portion thereof for supplying heavier liquid to said chamber, said nozzle passing through a plurality of the innermost partition walls whereby the inner portion of said rotor effects demulsification and clarification of the lighter liquid prior to its removal therefrom, and means for removing lighter liquid from the innermost portion of said rotor chamher.

6. In apparatus for countercurrent exchange between at least partly immiscible liquids of different densities, one of which carries solids, a shaft carrying spaced disks and an outer cylindrical wall forming a rotor chamber, a disk within the rotor chamber spaced from one wall thereof and having its outer edge spaced from the cylindrical outer wall of the rotor chamber to provide an annular outlet passage for heavier liquid from said chamber, spaced partition walls within said chamber, each secured at one side to the inner side of said inner disk, said walls forming successive passages of progressively increasing radius, means being provided for closing the opposite sides of said passages, openings in said walls for passage of fluid therethrough, the openings in each of said walls being of substantially uniform size, said openings in adjacent walls being staggered with respect to each other, the outer portion of said rotor being free of said walls, the inner portion of said cylindrical outer wall of the rotor being provided with a sloping surface, the outermost portion of which extends to the space between the periphery of the inner disk and the cylindrical wall of said rotor chamber, whereby heavier liquid and solids carried thereby are directed through said annular opening to the inter-disk space between said inner disk and the outer rotor wall adjacent thereto, means for supplying heavier liquid to and removing lighter liquid from the inner portion of said rotor chamber, means for removing heavier liquids carrying suspended solids from said interdisk space at the innermost part thereof, and means for introducing lighter liquid into the outer portion of said rotor chamber, said last mentioned means being spaced internally from the aforesaid annular opening to the interdisk space, whereby the outer space within the rotor chamber serves for demulsifying the heavier liquid prior to its removal therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 1,887,476 Lindgren Nov. 8, 1932 2,176,982 Thayer Oct. 24, 1939 2,209,577 Podbielniak July 30, 1940 2,281,796 Podbielniak May 5, 1942 2,286,157 Podbielniak June 9, 1942 2,291,849 Tornlinson Aug. 4, 1942 2,619,280 Redlich Nov. 25, 1952 

1. IN APPARATUS FOR COUNTERCURRENT EXCHANGE BETWEEN AT LEAST PARTLY IMMISCIBLE LIQUIDS OF DIFFERENT DENSITIES, ONE OF WHICH CARRIES SOLIDS, A ROTOR PROVIDED INTERNALLY WITH A ROTOR CHAMBER, SPACED PARTITION WALLS WITHIN SAID CHAMBER SURROUNDING THE AXIS OF THE ROTOR AND FORMING SUCCESSIVE PASSAGE OF INCREASING RADIUS, THE ELEMENTS OF SAID WALLS BEING PARALLEL TO THE AXIS OF SAID ROTOR, OPENINGS IN EACH OF SAID WALLS FOR PASSAGE OF FLUIDS THERETHROUGH, THE OPENINGS IN EACH OF SAID WALLS BEING OF SUBSTANTIALLY UNIFORM SIZE AND SPACED OVER THE SURFACES OF SAID PARTITION WALLS INTERMEDIATE THEIR EDGES, THE OPENINGS IN ADJACENT WALLS BEING STAGGERED WITH RESPECT TO EACH OTHER TO PROVIDE AN IMPERFORATE PORTION OF AN ADJACENT WALL OPPOSITE EACH OPENING IN EACH WALL THROUGH THE ROTOR EXCEPT FOR THE INNERMOST AND OUTERMOST PERFORATED PARTITION WALLS, CLOSURE MEANS BEING PROVIDED AT THE ENDS OF SAID WALLS TO PREVENT FLOW THEREBETWEEN EXCEPT THROUGH SAID OPENINGS, THE OUTER PORTION OF SAID ROTOR CHAMBER BEING FREE OF SAID PARTITION WALLS AND PROVIDED INTERNALLY WITH A SLOPING SURFACE, THE OUTERMOST PORTION OF SAID SLOPING SURFACE EXTENDING TO A DISCHARGE PASSAGE FOR THE HEAVIER LIQUID AND SOLIDS CARRIED THEREBY, MEANS FOR SUPPLYING HEAVIER LIQUID TO AND REMOVING LIGHTER LIQUID FROM THE INNER PORTION OF SAID ROTOR CHAMBER, MEANS FOR REMOVING HEAVIER LIQUIDS CARRYING SUSPENDED SOLIDS FROM THE OUTERMOST PORTION OF SAID ROTOR CHAMBER THROUGH SAID DISCHARGE PASSAGE AND MEANS FOR INTRODUCING LIGHTER LIQUID INTO THE OUTER PORTION OF SAID ROTOR CHAMBER, SAID LAST NAMED MEANS BEING SPACED INTERNALLY FROM THE OPENING OF THE AFORESAID DISCHARGE PASSAGE FOR HEAVIER LIQUID AND SOLIDS TO PROVIDE AN OUTER SPACE WITHIN THE ROTOR CHAMBER FOR DEMULSIFYING THE HEAVY LIQUID PRIOR TO ITS REMOVAL. 